Incidence of Intravascular Uptake in Lumbar Spinal Injection Procedures

Study Design: Multicenter, prospective, observational study.

Objectives: To document the incidence of and factors associated with intravascular uptake during lumbar spinal injection procedures.

Summary Of Background Data: In prior reports, the incidence of inadvertent intravascular needle placement during contrast-enhanced, fluoroscopically guided lumbar spinal injection procedures has been incidentally noted to range from 6.4% to 9.2%. We present the first systematic prospective documentation of intravascular uptake of contrast dye during different types of lumbar injection procedures.

Methods: Fifteen interventional spine physicians in seven centers recorded data regarding intravascular uptake during 1219 contrast-enhanced, fluoroscopically guided lumbar spinal injection procedures.

Results: The overall incidence of intravascular uptake during lumbar spinal injection procedures as determined by contrast enhanced fluoroscopic observation is 8.5%. Caudal and transforaminal routes have the highest rates at 10.9% and 10.8%, respectively, followed by zygapophyseal joint (6.1%), sacroiliac joint (5.3%), and translaminar (1.9%) injections. Intravascular uptake is twice as likely to occur in those patients over rather than under 50 years of age. Preinjection aspiration failed to produce a flashback of blood in 74% of cases that proved to be intravascular upon injection of contrast dye.

Conclusion: The incidence of intravascular uptake during lumbar spinal injection procedures is approximately 8.5%. The route of injection and the age of the patient greatly affect this rate. Absence of flashback of blood upon preinjection aspiration does not predict extravascular needle placement. Contrast-enhanced, fluoroscopic guidance is recommended when doing lumbar spinal injection procedures to prevent inadvertent intravascular uptake of injectate.